ch 24

Question 1

The collective term for the organisms living on or in the human body, as opposed to a general
term for organisms in an environmental habitat, is

Answer 1

The human microbiome

Question 2

A close and long-term biological interaction between two different organisms is called a

Answer 2

symbiotic relationship

Question 3

probiotics are

Answer 3

live bacteria that promote the development of a healthy microbiome in the
gastrointestinal tract

Question 4

Prebiotics are
A) chemicals that are used to inhibit the growth of pathogenic bacteria
B) chemicals that are administered prior to beginning antibiotic therapy
C) chemicals used to inhibit the growth of pathogenic bacteria
D) chemicals that inhibit the growth of early life forms such as viruses
E) none of the above

Answer 4

none of the above

Question 5

Resilient microbial communities are

Answer 5

communities that resist damage and recover quickly after a disturbance.

Question 6

The vaginal microbiome of healthy reproductive age women

Answer 6

are often dominated by species of Lactobacillus.

Question 7

A core microbiome consists of

Answer 7

Microorganisms that are always found at a particular body site.

Question 8

The vaginal microbiomes of reproductive age women
A) Is relatively constant over time in women of the same ethnic group
B) Are “personalized” and the composition varies widely among women.
C) Typically have a low pH less than 5.5
D) All of the above.
E) None of the above.

Answer 8

all the above

Question 9

Fecal transplants are

Answer 9

done to cure infectious disease caused by Clostridium difficile

Question 10

Which of the following is NOT true about bacterial vaginosis
A) is diagnosed based on vaginal symptoms that include a ‘fishy odor’, elevated pH, the
presence of ‘clue’ cells, and a thin white vaginal discharge.
B) Increases risk to sexually transmitted infections.
C) Increases risk to preterm birth.
D) Is caused by a bacterial infection of the vagina.
E) All of the above

Answer 10

Is caused by a bacterial infection of the vagina

Question 11

The damaged areas of teeth caused by organic acids produced by dental plaque are called

Answer 11

dental caries

Question 12

What is the role of fecal transplants in medicine?

Answer 12

They can provide a healthy microbiota to help treat Clostridium difficle infections

Question 13

Common probiotics include

Answer 13

Bifidobacterium species

Question 14

A microbial community that does not significantly change when exposed to stressors is called

Answer 14

resistant

Question 15

Clostridium difficile infections most often occur

Answer 15

following prolonged antibiotic treatment

Question 16

Which of the following is a benefit of studying the human microbiome?
A) It may allow for the development of personalized medical treatments.
B) It may allow for more finely targeted probiotics.
C) It may allow for increased recognition of disease biomarkers.
D) All of these answers are possible benefits.

Answer 16

all the above

Question 17

Which of the following is TRUE about research on the human microbiome?
A) Advanced nucleic acid sequencing techniques were needed before a good
understanding of its microbial abundance and diversity could be developed.
B) Culture-dependent techniques fully elucidated its microbial diversity.
C) Cultivation was unimportant in studying its microbial diversity.
D) None of the answers are correct.

Answer 17

Advanced nucleic acid sequencing techniques were needed before a good
understanding of its microbial abundance and diversity could be developed.

Question 18

Normal microbiota helps to ________ colonization of pathogenic organisms

Answer 18

prevent

Question 19

The collective term for the functional collection of microbes living on or in the human body, as
opposed to a general term for organisms in an environmental habitat, is

Answer 19

the human microbiome

Question 20

Extensive microbial growth in a thick bacterial layer on the teeth is called

Answer 20

dental plaque

Question 21

Which of the following is NOT a major question in the Human Microbiome Project?
A) Are differences in the relative abundance of different bacteria important?
B) Do differences in the human microbiome correlate with differences in human health?
C) Is there a correlation between microbial population structure and host genotype?
D) How can we reduce the number of microbes on the human body?

Answer 21

D) How can we reduce the number of microbes on the human body?

Question 22

The most heavily colonized human organ by bacteria is the ________, containing 1011‐1012
bacterial cells per gram

Answer 22

large intestine

Question 23

The human microbiome contains all

Answer 23

organism present in and on the body

Question 24

All microorganisms that live in the human body are harmful.

Answer 24

false

Question 25

A Gram stained sample of vaginal secretions shows the presence of relatively high numbers of
gram-positive rods and relatively low numbers of gram-variable rods. This is indicative of
bacterial vaginosis.

Answer 25

False

Question 26

The use of fecal transplants has dramatically improved outcomes for patients with Clostridium
difficile infections

Answer 26

True

Question 27

Probiotics do not contain living microbes

Answer 27

False

Question 28

Vaginal acidity in the adult female reproductive tract is due to acid production by species of
Lactobacillus.

Answer 28

True

Question 29

A healthy vaginal microbiome is dominated by Candida

Answer 29

False